Generally, this type of light quantity adjustment apparatus is known as a diaphragm apparatus and shutter apparatus in which a board having an exposure aperture is disposed in a shooting light path or projection light path, and a quantity of light passing through the exposure aperture of the board is adjusted with light quantity adjustment blades.
For example, Patent Document 1 (Japanese Utility Model Application Publication No. H06-87941) discloses a diaphragm apparatus in which two blade members that slide and travel in mutually opposite directions are disposed around an exposure aperture formed in a board and open and close the light path aperture from an open state to a close state.
This Patent Document 1 discloses the diaphragm apparatus in which a driving motor is installed on one side of the board having the exposure aperture in the center and operates the diaphragm blades that correspond to the blade members to adjust the light quantity.
To explain the light quantity adjustment apparatus of the invention, using the diaphragm apparatus disclosed in this Patent Document 1 as an example, described below are an installation structure of the driving motor on the board and technical issues that are the issue of the invention.
[General Driving Motor Installation State Diagram]
First, FIGS. 11 and 12 show a perspective view and principal-part exploded perspective view showing a support state of a driving motor on a base board in a conventional general diaphragm apparatus, and described is the general driving motor installation structure in the diaphragm apparatus disclosed in Patent Document 1.
As specifically shown in FIG. 13 (that corresponds to FIG. 2 in Patent Document 1), locking hooks 110 (that correspond to hooks 100a to 100d) are formed in a board 100 with an exposure aperture formed, catch portions 220 (that correspond to concave portions 3c) to catch the locking hooks 110 are formed in a coil frame 210 (that corresponds to the driving coil frame 3) constituting a driving motor 200 (that corresponds to the motor portion) installed on the board 100, and the locking hooks 110 and catch portions 220 constitute a hook locking mechanism for installing the driving motor 200 on the board 100. Then, by pressing the catch portions 220 of the driving motor 200 in the locking hooks 110 of the board 100, the catch portions 220 are locked in the locking hooks 110, and the driving motor 200 is installed on the board 100.
In addition, in the general hook locking mechanism like the driving motor installation structure as disclosed in above-mentioned Patent Document 1, in order for either one of the locking hook and the catch portion constituting the hook locking mechanism to cause elastic deformation by pressing the other one, at least the member causing elastic deformation is formed of a resin.